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Every air-launched aircraft I'm aware of, with the exception of the D-21 in combination with the M-21 carrier, has been launched by dropping it. Is there a reason why drop launches are preferred to "fly-off" launches from the top of the carrier?

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  • $\begingroup$ I guess flyoff require some engine power from child aircraft which might affect flying characteristic of parent aircraft. Hence fall-off then ignite is more preferable. $\endgroup$ – vasin1987 Nov 18 '14 at 21:19
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    $\begingroup$ Remember how the Shuttle glider was launched from a 747? All it takes is a zero-g maneuver called a parabola. By the way, this is also the preferred way to bail out from a high-performance aircraft without an ejection seat. Trim full nose-down but pull to keep the flightpath level, open canopy and seat buckle, and just let go of the stick. $\endgroup$ – Peter Kämpf Nov 23 '14 at 8:35
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Its much safer, you don't kill the carrier aircraft if you drop away and have a major aircraft malfunction. Gravity gives you the separation you need.

If you treat the two aircraft like a formation flight, which it essentially is, its dangerous for the critical aircraft to go belly up, ie blind, to the carrier. In an emergency the first step in formation flying is to ensure separation which the critical aircraft can't do because it can't see if it's clear to descend and it may not have the ability to laterally sidestep. Thus, a blind push on the nose could kill both aircrews.

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The test launches of the space shuttle (both US and USSR) were top launches. (though that was due to bulk more than aerodynamic considerations)

enter image description here

Drop launches get you out of the wake of the carrier faster and it is easier to get vertical separation by dropping than by climbing.

With fly-off you start in the turbulent area and then need to get enough speed to fly, and stay in front or above of the launching craft until flight has stabilized.

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  • $\begingroup$ Also, with fly-off, you're pointing your engines straight at the plane you just took off from, as soon as you start to climb: that could presumably be problematic. $\endgroup$ – David Richerby Nov 19 '14 at 2:09
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    $\begingroup$ And you are dangerously close to the tail ! $\endgroup$ – Antzi Nov 19 '14 at 4:37
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    $\begingroup$ @Antzi - Speaking of that, since the shuttle was unpowered, how did it manage to lift off from the carrier aircraft without drifting back into the tail? I always thought that when you pull back on the stick to climb, you gain altitude at the expense of speed. $\endgroup$ – Johnny Nov 21 '14 at 1:01
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    $\begingroup$ @Johnny My guess is the carrier aircraft pitched aggressively nose down to avoid collision after detachment. $\endgroup$ – Rhino Driver Nov 21 '14 at 3:43
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    $\begingroup$ There's video of the shuttle glide tests here: youtube.com/watch?v=v-YNcwc1ZME; the shuttle separates at around the 4:35 mark. $\endgroup$ – Roger Lipscombe Mar 6 '15 at 19:29
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If the plane is up the carrier and something go wrong, both planes crash. The first test of the USA Space Shuttle were done with a carrier having the shuttle on its top; it was for wind tests. A carrier having a plane to drop of a plane to take off from a carrier was tries to reach space at lower cost, planned in the 1970s and the tests done in the 1980s. A model with reservoir was chosen instead.

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